1. Field of the Invention
The present invention relates to a locking structure for a connector.
The present application is based on Japanese Patent Application No. 2000-59288, which is incorporated herein by reference.
2. Description of the Related Art
A conventional locking structure for a connector as shown in FIG. 15, for example, is disclosed in Japanese Publication No. JP-U-61-60482 of unexamined Utility Model Application. FIG. 15A is a sectional view of an essential part. FIG. 15B is a view as seen in a direction of an arrow A of FIG. 15A, and FIG. 15C is a view as seen in a direction of an arrow B of FIG. 15A.
A female connector housing 201 is provided with a lock arm 203 having elasticity, and the lock arm 203 has a hook portion 205 at its distal end. When a male connector housing 207 is inserted into the female connector housing 201, an engaging portion 209 of the male connector housing 207 pushes the hook portion 205 of the lock arm 203 upward, and a support portion 211 of the lock arm 203 is flexed to bring the lock arm 203 into a posture as shown by a dotted line in FIG. 15A. After the engaging portion 209 has passed over the hook portion 205 of the lock arm 203, the lock arm 203 is restored from the deformed posture allowing both the connector housings 201 and 207 to be locked.
In order to disengage the connector housings from the locked condition, a backward end portion 213 of the lock arm 203 is pushed down to bring the hook portion 205 of the lock arm 203 into a pushed up state in the same manner as done when the male connector housing 207 has been inserted, thereby disengaging the lock of the hook portion 205. In order to avoid, on this occasion, an excessive push up of the lock arm 203 (too much flexure of the support portion 211), the lock arm 203 is designed in such a manner that when the lock arm 203 is inclined by an angle xcex8 as shown in FIG. 15A, projections 215 formed on both side ends of the lock arm 203 in a lateral direction come in contact with stoppers 217, thereby to restrict an amount of flexure of the support portion 211.
However, the lock arm 203 is so constructed that an area from the hook portion 205 of the lock arm 203 to the backward end portion 213 has high rigidity lacking in flexibility, and flexible areas are concentrated on the support portion 211 only. In order to set a retaining force of the lock arm in a locked condition to be large, a thickness of the support portion 211 may be increased. However, operating force for disengaging the lock will be increased accordingly, which results in an increase of a stress on the support portion 211, and the support portion 211 will be likely to be broken. Alternatively, material having less rigidity may be employed without changing a shape, but tendency of the breakage will not be improved.
In view of the above, an object of the present invention is to provide a lock structure in which flexure of a locking member can be dispersed, and in addition, which has sufficient strength and is difficult to be broken.
In order to solve the above-described problem, the present invention is a locking structure for a connector which is adapted to disengageably lock a male connector housing and a female connector housing which are adapted to be engaged with each other by locking an engaging portion provided on one of the housings with a latch portion provided on the other of the housings, characterized in that the other connector housing includes the latch portion at an opposite side of flexible arms which are fixed at their one ends on a wall of the housing so as to extend in an engaging direction of the housings, and a disengaging lever portion which is connected at its one end to the latch portion so as to extend along the arms, and the disengaging lever portion rotates with the latch portion around a pivot which is movable when the lock is disengaged.
Therefore, a member resisting to displacement of the latch portion when both the housings are engaged is only the arms in a cantilever type, and by appropriately setting a length and a thickness of the arms for example, the arms are uniformly flexed along their full length. Since a stress will not be concentrated on base end portions of the arms, a flexural angle at the fixed ends of the arms is thus limited to be small, enabling the arms to be less breakable.
When the lock is disengaged, the latch portion rotates around the pivot together with the disengaging lever portion, whereby the locked condition will be disengaged. On this occasion, because the pivot of the rotation can be displaced, the latch portion can rotate without resistance, and the arms which have been in the flexed state will not be subjected to an undue load. Therefore, the problem of shortage of strength will not happen.
According to the second aspect of the present invention, there provided a locking structure for the connector as described above and characterized in that at least one of the disengaging lever portion and the wall of the housing has a support portion which serves as the pivot of the rotation of the latch portion.
Accordingly, similar actions and effects to those of the above-described invention of can be obtained, and at the same time, flexibility of designing the support portion will be increased.
According to the third aspect of the present invention, there is provided a locking structure for the connector as described above and characterized in that the pivot of the rotation is provided at either one of a substantially same position as the fixed ends of the flexible arms in the engaging direction, and a position on a lock disengaging operation section.
Accordingly, similar actions and effects to those of the above-described inventions can be obtained, and at the same time, because the length of the arms is substantially equal to a radius of the rotation of the latch portion, strength of the fixed ends of the arms can be easily set.
According to the fourth aspect of the present invention, there is provided a locking structure for the connector as described above and characterized in that the disengaging lever portion includes the lock disengaging operation section at an opposite side to the latch portion interposing the support portion, and a distance between the support portion and the latch portion is set to be larger than a distance between the support portion and the lock disengaging operation section.
Accordingly, similar actions and effects to those of the above-described inventions can be obtained, and at the same time, operating force and operating stroke of the disengaging operation section required for disengagement of the lock can be appropriately and easily set.
According to the fifth aspect of the present invention, there is provided a locking structure for the connector as described above and characterized in that the disengaging lever portion is connected to the connector housing by means of a hinge at an opposite side to the latch portion interposing the pivot.
Accordingly, when the connector housing is molded, dimensional stability with respect to a position of the disengaging lever portion and a position of the support portion will be enhanced.
According to the sixth aspect of the present invention, there is provided a locking structure for the connector as described above and characterized in that the locking structure further includes lever side excessive displacement preventing pieces provided on both sides of a finger touch portion which is positioned at an opposite side to the latch portion, and housing side excessive displacement preventing pieces provided on the female connector housing and against which the lever side excessive displacement preventing pieces are adapted to be abutted thereby to prevent an excessive displacement of the disengaging lever portion in a locking direction.
Accordingly, when an external force in the locking direction is inadvertently applied to the disengaging lever portion, the lever side excessive displacement preventing pieces are abutted against the housing side excessive displacement preventing pieces, whereby the excessive displacement of the disengaging lever portion in the locking direction will be prevented.
According to the seventh aspect of the invention, there is provided a locking structure for a connector described as the sixth aspect of the present invention and characterized in that the female connector housing includes an outer wall which covers upper parts of the arms up to the latch portion, an inner face of the outer wall having an excessive displacement preventing wall portion against which the latch portion is adapted to be abutted thereby to prevent an excessive displacement of the disengaging lever portion in a lock disengaging direction.
Accordingly, similar actions and effects to those of the invention described as the sixth aspect of the present invention can be obtained, and in addition, when an external force in the lock disengaging direction is inadvertently applied to the disengaging lever portion, the latch portion is abutted against the excessive displacement preventing wall portion, whereby the excessive displacement of the disengaging lever portion in the lock disengaging direction will be prevented.